Portable crane



Jan. 21, 1947. c H, A, WAGNER Em 2,414,573

PORTABLE CRANE 7 Filed May 8, 1944 2 Sheets-Sheet 2 Fun. 3

l I I B3 II! H b0 41 INVENTORS new Gusmvs H. Wnenaa Patented Jan. 21, 1947 UNITED OFFICE PORTABLE CRANE Harold A. Wagner and Gustave H. Wagner, Portland, Oreg.

Application May 8, 1944, Serial No. 534,595

6 Claims.

The present invention relates to cranes or the like machines equipped with mechanism for hoisting, swinging, excavating or similar work. The general object of the invention is to provide a new and improved cab structure and rotatable supporting arrangement therefor.

It is desirable to mount the cab of machinery of the class described upon the base structure for rotation about a vertical axis so that the crane, shovel or the like device may be operated throughout 360 degrees, or at least throughout a relatively wide working angle. Ordinarily the mounting arrangement for such cabs comprises a turntable including a pair of tracks, one mounted upon the base structure, the other secured to the bottom of the cab with a multiplicity of rollers arranged therebetween. Such a track and roller arrangement supports the vertical load while additional means either in the form of a center pin or underhooking rollers must be provided for countereffecting the turning moments in the vertical plane resulting from loading of the extended boom. Such cab supporting arrangements as these which have been provided heretofore have been relatively complicated. expensive to manufacture and particularly diflicult and costly to maintain because of the extremely large number of wearing surfaces and which furthermore are normally operated under extremely high stresses.

Particularly in the caseof portable truck mounted cranes or shovels, in which instances the diameter of the turntable is limited by the width of the vehicle frame. the maximum available lever arm through which the turning moment in the vertical plane of the loaded boom can be counterbalanced is extremely short, In the case of a center pin anchorage, the maximum reaction lever arm is limited to the radius distance of the turntable while in the track underhooking anchorage arrangements the lever arm is limited to the diameter of the turntable. With such short reaction lever arms the load stresses are extremely high so that the turntable parts must be designed in heavy, clumsy proportions and which constitute a major portion of the weight of the machine. The power requirements for rotatably operating such turntables in the highly stressed condition is very considerable and, furthermore, accurate control of the rotational movements of the turntable is difiicult.

It is an obect of the present invention, therefore, to provide a new and improved mounting arrangement for machinery such as cranes, shovels and the like for rotation about a vertical axis, which arrangement is of a relatively simple design, of low manufacturing and low maintenance cost.

Another object of the invention is to'provide a new and improved mounting arrangement for machinery of the class described whereby a high degree of stability is obtained with a minimum of bearing surfaces. i

A still further object of the invention is to provide a new and improved rotatable mounting arrangement for cabs of machinery such as cranes, shovels and the like whereby the turning moments resulting from loading of the boom are resisted through relatively long lever arms in the cab mounting.

More specifically, it is an object to provide a relatively light weight, efficient and inexpensive rotatable mounting arrangement for truck mounted machinery cabs such as cranes, shovels and the like whereby a high degree of stability is obtained within the dimension limitations of I the vehicle.

In accordance with the illustrated embodiment of the invention the mounting arrangement for the cab comprises a pair of concentric structural frusto-conical members, the inner one of which has its lower end rigidly secured between the longitudinal frame members of the truck vehicle. The outer frusto-conical member is rotatably supported upon the uppermost end of the inner frusto-conical member with a suitable frictionless bearing arrangement provided therebetween; Surrounding the inner frusto-conical member adjacent the lower end of the outer frusto-conical member is a track a ainst which is adapted to ride a plurality of radially spaced rollers mounted on the lower end of the outer frusto-conical member. A pair of horizontal rails extending parallel with each other are rigidly secured to the lower end of the outer frusto-conical member, the front ends of these rails forming a pivotal anchorage for the lower end of the boom. A mast frame is provided on the side of the frusto-conical member structure opposite the boom. the upper end of the mast frame being rigidly braced to the upper end of the outer frusto-conical member and to the rear ends of the horizontal rails. With the supporting arrangement shown the rotation of the cab even .under loaded boom conditions may be effected with minimum power requirements and with accurate control.

Additional objects and advantages of the invention will appear from the following description taken in connection with the accompanying drawings while the features of novelty will be pointed 3 out with greater particularity in the appended claims.

In the drawings Fig, 1 is a side elevation of a truck mounted crane apparatus provided with a cab structure constructed in accordance with the present invention; Fig. 2 is a longitudinal crosssectional view through the cab shown in Fig. 1; Fig. 3 is a plan view of the structure shown in Fig. 2; Fig. 4 is an end elevation taken along the line 4-4 of Fig. 2; and Fig. 5 is a sectional view taken along the line 55 of Fig. 2.

Referring to the drawings, in Fig. 1 is shown 4 relative to the track 39 may be adjusted for the compensation of wear. The rollers 3I, 32 and 33 are rotatably mounted upon the outside of the outer cone I6 and extend through cooperating openings provided therein into cooperative em gagement with the track 35]. With this mounting arrangement of the rollers they are readily accessible for servicing or replacement.

The base of the cab I2 is defined in part by a pair ofparallel rails 49 and M extending longitudinally of the cab on each of the opposite sides a truck vehicle I0 having a relatively fiat bed II upon which is mounted a crane comprising a cab structure indicated generally at I2 and a boom I3. It will be understood that while a crane is referred to specifically, the present invention is not to be so limited to one specific type of apparatus but is equally applicable with other machinery apparatus. I e

The crane unit 'I2-I 3 .is mounted by means of a supporting structure upon the truck. for rotation about a vertical axis in order that the boom may be operated throughout 360 degrees rotation or, at least, throughout a relatively wide angle. The supporting structure comprises a pair of conical-shaped members I5 and I6 which may be rolled of metal plate and welded along the seam so as to form. structural units of high strength. The cones are substantially similar to each other except that the inner one is slightly the longer- The inner frusto-conical member I5 is rigidly secured at its lower end to the bed of the truck the lower end o'fthefrusto-conical member preferably extending downwardly be tween the, longitudinal truck frame members I8. A pair of transverse frame members I9may be provided between the frame members I8 for further increasing the rigidity of the anchorage for the bottom of the frusto-conlcal member. The outer frusto-conical member I6 depends concentrically over the inner frusto-conical member and is rotatably mounted thereupon by means of suitable frictionless bearings arranged between the adjacent upper ends. A vertical shaft 2I is secured co-axially with the inner frusto-conical member by means of spaced discs 22 and 23, the upper end of the shaft 2| extending beyond the ppe e d of the frusto-conical member I5. The upper end of the frusto-'-conica1 member I6 is provided with a disc member 24 secured radially therein and defining a support surface between which and the disc top 23 of'frusto-conical member I5 is arranged the vertical thrust-bearing assembl'y'26. Welded to the upper surfaceof the 0 disc 24 is a ring .2! defining a backing shoulder for the horizontal thrust bearing assembly 28 arranged about the uppermost end of the shaft 2i.

The base portion of the inner frusto-conical member I5 is provided" with a circumferentially extending track 30 having, a cylindrical outer surface upon which is adapted to ride a plurality of rollers suitably mounted upon the lower portion ;-of the outer frusto-conical member I6. As illustrated more clearly in th sectional view of Fig. 5a. pair of rollers 3] and 32 are mounted upon the side of the outer frusto-conical mem- .ber facing the forward end of the cab and spaced 90 degrees apart. A single roller 33 is provided on the side of the outer frusto-conical member directly opposite the rollers 3| and 32. The roller 33 is mounted upon a shaft which is eccentric of the bearing support therefor, and has a lever 35 rigidly secured to an extension of the shaft by means of which the position of the roller 33 of the outer frusto-conical member I5. The rails t0 and 4| are welded to the upper surface of a ring member 42 which is in turn welded onto the lower end of the frusto-conical member I6 and are further secured to the frusto-conical memher by the rectangular plate 43 which is cut out and welded around the frusto-conical member IE a slight distance abov the ring 42. The rollers SI, 32 and 33 may conveniently be mounted between the plate 43 and the bottom ring 4-2.; The boom I3 may be pivotally secured as by the shaft 45 to the forward ends of therails ill and 4 I which terminate relatively close to, the forward side of the outer frusto-conical member in order that the lever arm between the base of the boom and the forward'rollers 3I and 32 1upon the frustoconical member support will be relatively short. In this regard, it will be observed that the rollers 3i and 32 are substantially on the horizontal line of the pivotal support of the base of the boom. The rails All and 4| extend for a considerable distance rearwardly of the frusto-conicalmember structure and the crane operatin machinery (not shown) such as the motor, winch lever arm minimizes the resultant horizontal thrust of the boom upon the frusto-conic al member'supporting structure.

Cables 58 connected to the outer end of the boom I 3 extend through a pulley combination 5| provided on a masthead arranged on the opposite side'of the frusto-conical member structure with respect to the base of the boom. The frame work of the mast includes a pair of rearwardly and downwardly extending members 52 welded to the rear end portions of the rails 40 and M and forwardly extending frame members 53 which are welded to a transversely extending bracket 54 secured to the uppermost end of the outer frustoconical member I6.

bracket 54 downwardly to the rails 40 and 4|.

. The bed I I of the truck vehicle is provided with a ring gear 60 with which may be meshed a drive pinion fil mounted on the end of shaft 62 depending from the bottom of the cab and which may be connected through suitable drive mechanism (not shown) to the engine within'the cab. A protective ring 63 may also be secured to the bottom of the cab for safeguarding against damage to either the pinion or ring gear; .The ring 53 also provides a means for supporting the cab unit when it is lifted from the truck vehicle and deposited upon the ground. It will be observed that the cab structure may readily be lifted off of the inner frusto-conical member I5 without requiring any detachment operations.

The housing for the cab structure may assume any desired form for enclosing the crane operating machinery and also providing a control partment for the craneoperator. The particular cab enclosure in combination with the particu-' A pair or" additional brace. 7 members 55 extend from the outer ends of the lar type of boom shown in the drawing is described in greater detail in our co-pending patent application, S. N. 528,212, filed March 27, 1944. It will be observed, however, that the pres ent invention is not limited in its applicability i by details of the cab housing or boom design.

It will be apparent to those skilled in the art that the turning moment in the vertical plane of the loaded boom is supported, or counteracted, in the present mounting without highly stressing any of the structural-elements, and particularly the lateral thrust bearings, because of the relatively long lever arms provided for the reaction forces. Because of the fact that the rollers 3l33 riding upon the track 30 are substantially in, or even slightly below, the horizontal plane of the base of the boom while the upper bearings are relatively closely adjacent the point of application of force through the cables 50, the lever arms for the reaction forces provided by the conical mounting arrangement are substantially equal to the lever arms of the applied load forces. For this reason the bearing means at both the lower and upper ends of the cones may be of a relatively simple inexpensive design. Furthermore due to the structural arrangement in general all of the bearings may be substantially enclosed whereby dust, sand and other foreign matter is readily excluded from the wearing surfaces so that the maintenance cost may be kept at a minimum.

Having described the invention is what is considered to be a preferred embodiment thereof it is desired that it be understood that the specific details shown are merely illustrative and that the invention can be carried out by other means.

We claim:

1. A portable crane apparatus comprising a truck vehicle including a frame, a crane unit mounted upon said frame, said crane unit including a cab mounted upon said frame, a boom pivotally secured to the base of said cab at the forward end thereof, a pulley frame adjacent the upper portion of said cab, boom operating cables extending between said pulley frame and the outer end of said boom, means for supporting said crane unit upon said vehicle frame comprising an inner conical member secured at the base to said vehicle frame and extending upwardly within said cab, an outer frusto conical member rigidly secured to said cab, said pulley frame being secured to the upper end of said last mentioned member, bearing means arranged between the adjacent upper ends of said frusto conical members, a track extending around the lower portion of said inner frusto conical member, a pair of rollers mounted in the base of said cab adjacent the forward end thereof for riding upon said track, and adjustable roller means secured to said cab base on the opposite side portion of said conical members with respect to said first pair of rollers engageable with said track.

2. An apparatus of the class described, a truck vehicle including a pair of longitudinal frame members, a cab mounted upon said truck vehicle for rotation about avertical axis, means supportting said cab on said vehicle comprising a pair of concentric frusto-conical members, the lower end of the inner frusto-conical member depending between said truck frame members and secured rigidly thereto, the outer frusto-conical member being rotatably supported upon the upper end of the inner frusto-conical member, circumferentially spaced bearing means arranged between the lower end portions of said frustoconical members, a pair of horizontal rails secured intermediate their ends to the lower end of said outer frusto-conical member, a boom pivotally secured to the forward ends of said rails, a mast on the opposite side of said frusto-conical members with respect to said boom, said mast beingrigidly secured to the upper end of said outer cone and to the rear end portions of said rails.

3. An apparatus of the class described comprising 'atruck' vehicle including a pair oflongitudinal frame members, a cab mounted uponsaid truck vehicle for rotation about a vertical axis, the mounting means for said cab comprising a pair of concentric frusto-conical members, the lower end of the inner frusto-conical member being rigidly secured to said truck frame members, the upper end of said inner frusto-conical member extending upwardly in said cab to a point adjacent the upper portion thereof, the outer frusto-conical member being rotatably supported upon the upper end of said inner frusto-conical member, bearing means arranged between the lower end portions of said frusto-conical members, a pair of parallel longitudinal members rigidly secured intermediate their ends to each of the opposite side portions of said outer frustoconical member adjacent the lower end thereof, a boom pivotally secured to the forward. ends of said members, a, mast rigidly secured to the upper end of said outer frusto-conical member and extending upwardly therefrom, means anchoring said mast to the rear ends of said members, and cables extending between said mast and the outer end portion of said boom.

4. A supporting arrangement for a crane or the like apparatus comprising a pair of concentric frusto-conical members, the lower end of the inner cone being rigidly anchored, the upper end of the outer frusto-conical member being rotatably supported upon the upper end of the inner frusto-conical member, circumferentially spaced bearing means arranged between the lower end portions of said frusto-conical members, a pair of parallel longitudinal members rigidly secured intermediate their ends to opposite side portions of the outer frusto-conical member adjacent the lower end thereof, a boom pivotally secured to the forward ends of said members on the forward side of said frusto-conical members, a mast rigidly secured to the upper portion of said outer frusto-conical member and anchored to the rear ends of said longitudinal members on the opposite side of said frusto-conical members with respect to said boom, and boom operating means extending between said mast and said boom.

5. A supporting arrangement for a crane or the like apparatus comprising a pair of concentric overlapping frusto-conical members, the inner cone being rigidly anchored at its lower end, bearing means arranged between the adjacent upper ends of said frusto-conical members, a pair of parallel, longitudinal, horizontal members secured intermediate their ends to the opposite side portions of said outer frusto-conical member adjacent the lower end thereof, a boom pivotally secured to the forward ends of said members, a plurality of radially spaced bearing means mounted on the forward side of said outer frustoconical member for engaging against the lower portion of said inner frusto-conical member, adjustable bearing means mounted on the rearward side of said outer frusto-conical member for engaging the lower portion of said inner frustoconical member, a mast on the opposite side of said frusto-conical members with respect to said boom, said mast including members rigidly secured to the upper end of said outer frusto-conical member and other members extending downwardly and rearwardly and secured to the rear end portions of said longitudinal members.

6.'A supporting arrangement for a crane or the like apparatus comprising ,a pair of concentric frusto conical members of similar taper, the lower end of the inner member being rigidly anchored, the upper end of the outer member being rotatably supported upon the upper end of the inner member, a shaft secured to and extending axially upwardly from said inner member, vertical and lateral thrust bearing means arranged about saidshaft and engagedby said outer member, circumferentially spaced bearing means arranged between the lower end portions of said members, a boom pivotally secured to structure extending from the forward side of said outer conical-member, a mast rigidly secured to the upper portion of said outer conical member, and boomoperating means extending between said mast and the outer end'of said boom.

HAROLD A. WAGNER. GUSTAVE' H. WAGNER. 

